Draconis
ElCeejo

Adds advanced Dragons and powerful equipment.

Alien Material
debiankaios

Adds new blocks, items, and tools from aliens. A new time begins.

Multiple Biome Generator
chaosomnium

230 Pseudorandomly Generated Biomes, Trees, Fruits, Ores, Tools, and Liquids

Base Modpack
karlexceed

This combines several other mods that I consider a basic minimum starting point for worlds.

Trucraft
PolySaken

An alternative crafting system done entirely in the world.

Kitty/Kitto Ores
nemokitty9

Nemokitty9's own ore pack. Includes Tools!